Can I screen just for a single sector - like oil and gas?

Yes, we do provide screening across all the industries in the Thomson Reuters TRBC business classification system which consists of 10 economic sectors and 124 industry groups. You can add them to a stock screen by selecting the “Sector/Industry” rule type, then choosing which level of the hierarchy to add, and which sectors/industries to include or exclude:

Using our Sector Browser, you can also browse up and down our sector hierarchy, sorting the key ratios for a given sector to find, say, the stock with the highest momentum or the cheapest on a PE multiple basis.

Another way to browse sectors is via the FTSE Sector Indices which is a separate classification system from the TRBC one that we use around the site.